I've always thought the Schumacher ballcups are the best.
One tip for anyone buying the Mi3. Make sure you buy at least 2-3 of the U3131 Alloy shim kit. You need these and you need many of them depending on the setups you will be running. I am also hoping that at one point they'll make a .25 shim as well. I know there are other shims on the market you can use but the Schuie ones, nice and polished are just pimp!